For ADHD, we have carried out a case-control study in a local school district. We have recently published a description of the psychometric properties of the screening instruments used to assess disease status. We have also submitted an analysis of how changing case definitions and subtyping rules can influence the proportion of subjects designated as Predominantly Inattentive, Predominantly Hyperactive-Impulsive, or Combined Type ADHD in an epidemiologic study. We are also estimating ADHD prevalence among elementary school children in this county. (see Z01 ES49034-11; PI Dale Sandler, EB)[unreadable] [unreadable] For ALS, based on a case-control study that we conducted, we examined lead as a risk factor and possible genetic modifiers of risk. Recently we have published an examination of the role of head injury as a risk factor for ALS and have submitted an analysis suggesting that higher lead levels in bone are associated with longer survival after diagnosis in ALS cases. We are writing a proposal to study the relationship between blood lead levels, biomarkers of bone turnover (indicators of mobilization of lead sequestered in bone), and risk of ALS using the Veterans Administration ALS cohort. (see Z01 ES49005-16; LI Freya Kamel, EB) [unreadable] [unreadable] We have carried out a case-control study nested within the Agricultural Health Study to examine associations between Parkinson's disease and environmental risk factors, particularly certain pesticide exposures. We will also look at selected candidate genes as susceptibility factors. This study will make use of data from the Agricultural Health Study as well as additional questionnaire data and field samples collected expressly for this effort. Field work for this study has recently ended and examination of the data is getting underway. (see Z01 ES44007-07 EB; LI Freya Kamel, EB) [unreadable] [unreadable] The pilot study of the effects of soy estrogen on neonatal development is now out of the field and data analysis is underway. We are examining physical markers of development using a modified Ballard scale, ultrasound images of putatively estrogen-sensitive organs, and hormone levels. (see Z01 ES44006-06 EB; PI Walter Rogan, EB)